Revert "[CONTRIBUTING] Add non specified dependencies"

This reverts commit 75c9cf8e2b5d85072a10f8ef53fc23ec811c29cd.

CONTRIBUTING.md

@@ -26,15 +26,13 @@ ffmpeg -i my_big_image.jpg -vf scale=w=256:h=256:force_original_aspect_ratio=dec
 
 Then just run the `./autogen.sh` to generate the added or updated node classes.
 
-> IMPORTANT NOTE: To run `autogen.sh`, you need [round][round], [black][black], [jinja2][jinja2] and
+> IMPORTANT NOTE: To run `autogen.sh`, you need [round][round] and
 > [inkscape][inkscape] command lines that are used for cleaning the image
 > resource filenames.
 >
 > macOS users can download the inkscape via Homebrew.
 
 [round]: https://github.com/mingrammer/round
-[black]: https://github.com/psf/black
-[jinja2]: https://pypi.org/project/Jinja2/
 [inkscape]: https://inkscape.org/ko/release
 
 ### Update Aliases
@@ -48,7 +46,7 @@ or update the `ALIASES` map in [config.py](config.py).
 
 Then just run the `./autogen.sh` to generate the added or updated aliases.
 
-> IMPORTANT NOTE: To run `autogen.sh`, you need [round][round], [black][black], [jinja2][jinja2] and
+> IMPORTANT NOTE: To run `autogen.sh`, you need [round][round] and
 > [inkscape][inkscape] command lines that are used for clearning the image
 > resource filenames.
 
@@ -58,10 +56,6 @@ Then just run the `./autogen.sh` to generate the added or updated aliases.
 python -m unittest tests/*.py -v
 ```
 
-> [graphviz][graphviz] is needed to run the tests
-
-[graphviz]: https://pypi.org/project/graphviz/
-
 ## Testing changes to the website
 
 The [Docusaurus](https://docusaurus.io/)-based documentation website can be run by installing dependencies, then simply running `npm run start`.